In Little Alchemy, a doctor is a person who can heal the sick and injured. Doctors can be created by combining a human with a potion. To make a potion, you will need to combine a plant with a water source. Once you have created a potion, you can then combine it with a human to create a doctor.
Doctors are an important part of Little Alchemy, as they can help to keep your population healthy and happy. A healthy population is more likely to survive and thrive, which can lead to a more successful game.